Today, as it has been for a century, American politics is an argument between two Princetonians -- James Madison, Class of 1771, and Woodrow Wilson, Class of 1879. Madison was the most profound thinker among the Founders. Wilson, avatar of "progressivism," was the first president critical of the nation's founding. Barack Obama's Wilsonian agenda reflects its namesake's rejection of limited government.

Lack of "a limiting principle" is the essence of progressivism, according to William Voegeli, contributing editor of the Claremont Review of Books, in his new book "Never Enough: America's Limitless Welfare State." The Founders, he writes, believed that free government's purpose, and the threats to it, are found in nature. The threats are desires for untrammeled power, desires which, Madison said, are "sown in the nature of man." Government's limited purpose is to protect the exercise of natural rights that pre-exist government, rights that human reason can ascertain in unchanging principles of conduct and that are essential to the pursuit of happiness.

Wilsonian progressives believe that History is a proper noun, an autonomous thing. It, rather than nature, defines government's ever-evolving and unlimited purposes. Government exists to dispense an ever-expanding menu of rights -- entitlements that serve an open-ended understanding of material and even spiritual well-being.

The cheerful assumption is that "evolving" must mean "improving." Progressivism's promise is a program for every problem, and progressivism's premise is that every unfulfilled desire is a problem.

Franklin Roosevelt, an alumnus of Wilson's administration, resolved to "resume" Wilson's "march along the path of real progress" by giving government "the vibrant personal character that is the very embodiment of human charity." He repudiated the Founders' idea that government is instituted to protect pre-existing and timeless natural rights, promising "the re-definition of these rights in terms of a changing and growing social order."

He promised "a right to make a comfortable living." Presumably, the judiciary would define and enforce the delivery of comfort. Specifically, there could be no right to "do anything which deprives others" of whatever "elemental rights" the government decides to dispense.

Today, government finds the limitless power of dispensing not in Madison's Constitution of limited government but in Wilson's theory that the Constitution actually frees government from limitations. The liberating -- for government -- idea is that the Constitution is a "living," evolving document. Wilson's Constitution is an emancipation proclamation for government, empowering it to regulate all human activities in order to treat all human desires as needs and hence as rights. Unlimited power is entailed by what Voegeli calls government's "right to discover new rights."

"Liberalism's protean understanding of rights," he says, "complicates and ultimately dooms the idea of a principled refusal to elevate any benefit that we would like people to enjoy to the status of an inviolable right." Needs breed rights to have the needs addressed, to the point that Lyndon Johnson, an FDR protege, promised that government would provide Americans with "purpose" and "meaning."

Although progressivism's ever-lengthening list of rights is as limitless as human needs/desires, one right that never makes the list is the right to keep some inviolable portion of one's private wealth or income, "regardless," Voegeli says, "of the lofty purposes social reformers wish to make of it."

Lacking a limiting principle, progressivism cannot say how big the welfare state should be but must always say that it should be bigger than it currently is. Furthermore, by making a welfare state a fountain of rights requisite for democracy, progressives in effect declare that democratic deliberation about the legitimacy of the welfare state is illegitimate.

"By blackening the skies with crisscrossing dollars," Voegeli says, the welfare state encourages people "to believe an impossibility: that every household can be a net importer of the wealth redistributed by the government." But the welfare state's problem, today becoming vivid, is socialism's problem, as Margaret Thatcher defined it: Socialist governments "always run out of other people's money."

Wilsonian government, meaning (in Wilson's words) government with "unstinted power," is hostile to Madison's Constitution, which, Madison said, obliges government "to control itself." Thus our choice is between government restraint rooted in respect for nature, or government free to follow History wherever government says History marches.